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#include "scope.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define DEFAULT_SIZE 4
static void scope_init(struct scope* scope) {
scope->types = calloc(DEFAULT_SIZE, sizeof(struct type_def*));
scope->type_cap = DEFAULT_SIZE;
scope->vars = calloc(DEFAULT_SIZE, sizeof(struct var_def*));
scope->var_cap = DEFAULT_SIZE;
}
static void scope_destroy(struct scope* scope) {
for (unsigned long long i = 0; i < scope->type_cap; i++) {
if (scope->types[i] != NULL) free(scope->types[i]);
}
free(scope->types);
for (unsigned long long i = 0; i < scope->var_cap; i++) {
if (scope->vars[i] != NULL) free(scope->vars[i]);
}
free(scope->vars);
}
unsigned long long hash_name(const char* name) {
unsigned long long hash = 0, i = 0;
while (name[i] != 0) hash = (hash << 5) - hash + name[i++];
return hash;
}
static struct type_def** type_cell(
const struct scope* scope,
const char* name
) {
unsigned long long orig_idx = hash_name(name) % scope->type_cap;
unsigned long long idx = orig_idx;
do {
if (scope->types[idx] == NULL
|| strcmp(name, scope->types[idx]->name) == 0)
return &scope->types[idx];
} while ((idx = (idx + 1) % scope->type_cap) != orig_idx);
return NULL;
}
static void rehash_types(struct scope* scope) {
struct type_def** old_types = scope->types;
unsigned long long old_cap = scope->type_cap;
scope->type_cap *= 2;
scope->types = calloc(scope->type_cap, sizeof(struct type_def*));
if (scope->types == NULL) {
fprintf(stderr, "ccc: out of memory\n");
exit(1);
}
for (unsigned long long i = 0; i < old_cap; i++) {
if (old_types[i] == NULL) continue;
struct type_def** cell = type_cell(scope, old_types[i]->name);
if (cell == NULL) {
fprintf(stderr, "ccc: types rehash failed, likely a bug\n");
exit(1);
}
*cell = old_types[i];
}
free(old_types);
}
static struct var_def** var_cell(
const struct scope* scope,
const char* name
) {
unsigned long long orig_idx = hash_name(name) % scope->var_cap;
unsigned long long idx = orig_idx;
do {
if (scope->vars[idx] == NULL
|| strcmp(name, scope->vars[idx]->name) == 0)
return &scope->vars[idx];
} while ((idx = (idx + 1) % scope->var_cap) != orig_idx);
return NULL;
}
static void rehash_vars(struct scope* scope) {
struct var_def** old_vars = scope->vars;
unsigned long long old_cap = scope->var_cap;
scope->var_cap *= 2;
scope->vars = calloc(scope->var_cap, sizeof(struct var_def*));
if (scope->vars == NULL) {
fprintf(stderr, "ccc: out of memory\n");
exit(1);
}
for (unsigned long long i = 0; i < old_cap; i++) {
if (old_vars[i] == NULL) continue;
struct var_def** cell = var_cell(scope, old_vars[i]->name);
if (cell == NULL) {
fprintf(stderr, "ccc: vars rehash failed, likely a bug\n");
exit(1);
}
*cell = old_vars[i];
}
free(old_vars);
}
void scope_push(struct scope** p_scope) {
struct scope* inner_scope = calloc(1, sizeof(struct scope));
scope_init(inner_scope);
inner_scope->next_out = *p_scope;
*p_scope = inner_scope;
}
void scope_pop(struct scope** p_scope) {
struct scope* discarded_scope = *p_scope;
*p_scope = (*p_scope)->next_out;
scope_destroy(discarded_scope);
free(discarded_scope);
}
void scope_install_default_types(struct scope* scope) {
scope_define_type(scope, (struct type_def) {
.name = "void",
.sz = 0,
});
scope_define_type(scope, (struct type_def) {
.name = "bool",
.sz = 1,
});
scope_define_type(scope, (struct type_def) {
.name = "char",
.sz = 1,
});
scope_define_type(scope, (struct type_def) {
.name = "short",
.sz = 2,
});
scope_define_type(scope, (struct type_def) {
.name = "int",
.sz = 4,
});
scope_define_type(scope, (struct type_def) {
.name = "float",
.sz = 4,
});
scope_define_type(scope, (struct type_def) {
.name = "long",
.sz = 8,
});
scope_define_type(scope, (struct type_def) {
.name = "double",
.sz = 8,
});
}
bool scope_get_type(
const struct scope* scope,
struct type_def* p_entry,
const char* name
) {
for (; scope != NULL; scope = scope->next_out) {
struct type_def** cell = type_cell(scope, name);
if (cell == NULL || *cell == NULL) continue;
if (p_entry != NULL) *p_entry = **cell;
return true;
}
return false;
}
void scope_define_type(struct scope* scope, struct type_def type) {
struct type_def** cell = type_cell(scope, type.name);
while (cell == NULL) {
rehash_types(scope);
cell = type_cell(scope, type.name);
}
*cell = calloc(1, sizeof(struct type_def));
if (*cell == NULL) {
fprintf(stderr, "ccc: out of memory\n");
exit(1);
}
**cell = type;
}
bool scope_get_var(
const struct scope* scope,
struct var_def* p_entry,
const char* name
) {
for (; scope != NULL; scope = scope->next_out) {
struct var_def** cell = var_cell(scope, name);
if (cell == NULL || *cell == NULL) continue;
if (p_entry != NULL) *p_entry = **cell;
return true;
}
return false;
}
void scope_define_var(struct scope* scope, struct var_def var) {
struct var_def** cell = var_cell(scope, var.name);
while (cell == NULL) {
rehash_vars(scope);
cell = var_cell(scope, var.name);
}
if (*cell == NULL) {
*cell = calloc(1, sizeof(struct var_def));
if (*cell == NULL) {
fprintf(stderr, "ccc: out of memory\n");
exit(1);
}
}
/* technically C allows redefinition :/ */
**cell = var;
}
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